The overall aim of our studies is to derive a potential HCV vaccine, based on the induction of HCV-specific CTL. To do so, we propose in the present Phase I study, to identify a synthetic formulation composed of at least two A2-restricted CTL epitopes derived from conserved regions of the HCV genome. Such formulation will also contain universal T helper epitopes and will be demonstrated to be efficacious in inducing specific A2-restricted CTL responses in vivo, utilizing HLA A2/Kb transgenic mice. In parallel studies additional potential epitopes specific for several of the major HLA types will also be identified. PROPOSED COMMERCIAL APPLICATION: The proposed research has two main specific applications relating to hepatitis C infection. l) Development of an original type of prophylactic vaccine specifically targeting HCV sequences that are highly conserved and/or derived from internal viral proteins, and 2) A therapeutic vaccine for chronic hepatitis C infection. This technology has wide applicability to other chronic viral diseases and cancer.